Tuesday, August 25, 2009

After having decided on Python 2.6 as a platform it's time to find an IDE and get on with a few tutorials. You may snicker at me wanting an IDE but I'm trying to keep the barrier to entry as low as possible initially so I don't get discouraged. I'm already coming in cold to Python and Ubuntu so having to learn emacs/vi as well is a step too far for me. Plus I have a .NET background so I'm used to the power of Visual Studio.

I decided on Eclipse as an IDE mainly because it's full-featured and is relatively equivalent to Visual Studio. I may take a look at Java as well so using the same IDE for multiple languages is a bonus.

PydevPydev is a plugin for Eclipse which supports Python development. This is where the journey gets a bit interesting. The organisation for Pydev is horrendous. Whereas projects like Python and Eclipse have easy to understand websites that provide a unified front, Pydev is all over the place.

Apparently Pydev is owned by Aptana although it is still free and open source. There are also "Pydev extensions" which provide some extra functionality, also free and open source. Why these are two distinct things escapes me and fragments the product. Some of the downloads are from SourceForce, some are from Aptana and others from Fabioz. All I wanted was a simple plugin, why not just bundle it all together as one Eclipse plugin with a link to the update site on the front page?

After going through the Getting Started section I had Pydev installed correctly and was ready to start. First things first, I need to download the Subclipse plugin which seamlessly integrates Subversion commands into Eclipse. So I find the update URL on the Subclipse site and enter it into Eclipse to which it replies "No features found on the selected site(s)". First roadblock.

Updating EclipseSo I Google 'Ubuntu Subclipse "no features found"' and I come up with a very limited result set. Some of them suggest using the Sun JDK instead of GCJ which I have no idea how to do. Others suggest making sure my Eclipse 3.2 version is up-to-date. I ask Eclipse for a list of updates and it asks me what mirror I wish to use, naturally I select Australia which gets me an error message saying there were network problems- 404 meaning the server is down. Great. So I try again with a US server, bingo! I assume I want to install the latest version which is 3.2.2 so I check that and continue. Up pops an error saying it can't find particular files and that the installation has failed. Second roadblock.

So I Google the error message and it turns out that I need to install Eclipse 3.2.1 before I can install 3.2.2. There seriously needs to be a version check before allowing me to witlessly try to install a version that can't be installed! Again I fire up the Eclipse update UI and find the 3.2.1 version (for some reason under "Find new features" rather than "Updates") and install it. Back to the update UI, I select 3.2.1 Patches as I assume I'll need this as well to update to 3.2.2. Trying to select that results in an error sayingEclipse Java Development Tools 3.2.1 performance patch (bug:159325) (1.0.0) requires feature "org.eclipse.jdt (3.2.1.r321_v20060905-R4CM1Znkvre9wC-)".

Great. Now where would I find that and why can't it just automatically resolve this dependency?I give up on this for now and take a look back at some of the other Google results for installing Subclipse.

Wrong Subclipse Version?Some results suggest it could be something to do with JavaHL, whatever that is. I find a link to a Tigris page explaining which versions of Subclipse are compatible with which versions of Subversion. I check my Subversion version which is 1.5.4 so apparently I want the 1.4.x version of Subclipse. I was trying to use the 1.6.x version previously which is probably why Eclipse didn't like that update URL. Whoops.

No luck with the 1.4.x version either, it still says "no features found ...". This is becoming a real hassle. I wish Subclipse was just another checkbox in Synaptic Package Manager so I could avoid all this fuss. I have to say that it hasn't been an easy experience so far and the initial respect I had for the environment has been marred by this wild goose chase.

Back To Updating EclipseHaving exhausted that line of inquiry I decide to update Eclipse again. One search result suggests opening Eclipse as a superuser using "sudo eclipse" and installing version Eclipse 3.2.2 SDK which works. I go back to the update UI and it's still showing me 3.2.1 Patches as an available option which seems weird considering I just upgraded to 3.2.2. I install 3.2.2 Patches and now I'm up to the latest version.

Back To Updating SubclipseConsidering everything's been working OK as superuser, I'll try to add the Subclipse plugin as superuser and see what happens. No luck, still says "no features found". Well my last resort is to add Subclipse as an archive. I shouldn't really have to do this but I'll give it a go, so I'll download the Subclipse zip file and add it to Eclipse as an archived site. This still doesn't work. Something is definitely missing from my Eclipse installation but I have no idea what. My solution is to install every update and feature for Eclipse that I can from the update site. OK almost everything in the Callisto Discovery site tells me that I need Eclipse RCP 3.2.2. WTF?!? I thought I just installed 3.2.2!

ReinstallI have decided to uninstall Eclipse and reinstall it via Synaptic Package Manager to start again from scratch. After a "Complete Uninstall" and reinstall I still have all of the updates I had applied. How in god's name am I supposed to revert to a plain vanilla Eclipse? Do I have to reinstall the OS?

As a programmer using squalid decades-old technology at work, I'm looking to delve into something more interesting in my spare time.

LinuxFirst of all I figured I'd look into this new Linux thing that everyone's talking about. The most approachable distribution seems to be Ubuntu so I initially downloaded Ubuntu 9.4 Desktop and tried it out in a virtual machine.

A very slick and easy to use installer let me set up all the essentials and get in to the desktop. I'm impressed that out of the box it has recognised my video card, network card and sound card. Everything is up and running nicely.

Then I took some time out to learn about how the file system is arranged in Linux and a few basic terminal commands. Next I want to get some tools installed so I can start a hobby LAMP project including a webapp, web services and MySQL/PostgreSQL. First of all I installed Eclipse, Subversion and Apache from Synaptic Package Manager. It's a very simple point-and-click GUI to install and update all software on the machine which is fantastic. I really wish Windows had this instead of a mixture of various updating mechanisms which each want to run in their own process. Apparently Windows 7 has this feature for drivers but not for applications.Python/Perl/PHPI shopped around and decided on learning Python to play around with. My initial field of candidates was Perl, PHP and Python. Perl is just too ugly and hacky- so many implicit rules to remember and it's OO syntax is obviously a bolted-on afterthought. I'll definitely use this at work though as there are plenty of times when a quick hacky regex script is just what I need. PHP looks good for hacking together code quickly but feels like a modern day VB6 which quickly turns into spaghetti code. It also shares the bolted-on OO syntax.

PythonA couple of the reasons that I chose Python are:- Google is using it fairly extensively and has contributed many performance updates to the interpreter. All of these languages are interpreted and therefore are much slower than their compiled counterparts. If some of the smartest programmers in the world (Google) are contributing to speed it up then it has the best chance at good performance.- Easy syntax, great library support and community- Google AppEngine can be used with Python which provides a free and highly scalable playground for me to test out my code. The only downside is I'd have to learn about the BigTable storage system which probably doesn't suit my needs right now.

Deciding between Python 2.6 and 3.1 was hard. 3.1 is the latest and greatest but in the real world I think 2.6 and earlier are almost universally used. For my career I think the best option is to go with 2.6 so any skills I learn are transferrable to the real world.

Next up you can see my struggles to get the tools I need working to start on my Python development.